1. Field of the Invention
The present invention relates to an electronic device, such as a digital camera or a cellular phone, which is provided with a speaker and a microphone.
2. Description of the Related Art
Conventionally, an electronic device provided with a speaker and a microphone is known, and some electronic device of this type is configured to hold the speaker and the microphone by a holder.
For example, Japanese Laid-open Patent Publication No. H9-271090 discloses a parts holder that has a microphone holding portion and a speaker holding portion, which are integrally formed together. With the parts holder, the microphone and the speaker can be held so as not to be detached easily from the parts holder and can be mounted at a time on a body of the electronic device through the parts holder, whereby the ease of assembling can be improved.
With the parts holder disclosed in Japanese Laid-open Patent Publication No. H9-271090, although the ease of assembling is improved, sound insulation for the speaker and microphone cannot be ensured. Accordingly, additional separate sound insulation parts other than the parts holder are required to ensure the sound insulation for the speaker and microphone, resulting in a problem of increase in the number of parts, in costs, and in the man-hours required for assembly.
In particular, in a case that the speaker and the microphone are disposed close to each other as with a small-sized image pickup apparatus, relevant parts are largely affected by each other in an assembled state due to fabrication errors and/or assembly errors thereof, which makes it difficult to ensure the sound insulation for the speaker and microphone.
Usually, cables or a flexible printed circuit board is used for the wiring for the speaker and microphone. However, in a case that cables are used for the wiring, noise from the speaker or from the outside tends to be superimposed on an output signal of the microphone. In a case that a flexible printed circuit board is used, it is necessary to dispose an output signal line of the microphone on one surface of a double-sided flexible printed circuit board and dispose a ground (GND) pattern on another surface thereof in order to prevent noise from being superimposed on the output signal of the microphone, causing increase in costs.
As with an audio device disclosed in Japanese Laid-open Patent Publication No. 2005-252945, it is possible to prevent noise from being superimposed on the output signal of the microphone by using a differential amplifier, but the use of the differential amplifier results in increased costs.